Stump cutting apparatus

ABSTRACT

A stump cutting apparatus including a cutting wheel with a plurality of tool holders secured to the cutting wheel. A plurality of apertures located in each of the tool holders. Each of said apertures having a cutting tool or tooth mounted therein whereby each tool holder supports more than one cutting tool or tooth.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/643,059, filed May 4, 2012.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a stump cutting apparatusand, more specifically, to a stump cutting apparatus having a rotatingmember or element and a cutting tool attached to the rotating member orelement.

2. Description of Related Art

Various types of stump cutting devices are known. One type includes arotatable member, such as a wheel or disk, having a plurality of cuttingtools fastened to the peripheral edge thereof. Another type includes arotatable member, such as a rotatable drum, having a plurality ofcutting tools fastened to an outer circumferential surface thereof.During operation, the rotatable member; e.g., the wheel, disk or drum,rotates such that the cutting tools engage and cut the stump. Varioustypes of cutting tools are used with either stump cutting apparatus. Thecutting tool typically includes a tool holder secured to the cuttingwheel or drum and a cutting tooth secured by the tool holder to thecutting wheel.

SUMMARY OF THE INVENTION

A stump cutting apparatus including a hub having an axis of rotation anda member extending outwardly from the hub and having a plane of rotationtransverse the axis of rotation of the hub. The member includes a firstside surface, a second side surface wherein the first side surface andsecond side surface are generally parallel to the plane of rotation ofthe member. A support surface extends between the first side surface andthe second side surface with the support surface having a proximal endand a distal end. The distal end is closer to the hub. A tool holder issecured to the support surface. In one example of the present invention,the tool holder includes a plurality of apertures with each of theapertures having a cutting tool or tooth mounted therein. Accordingly,each tool holder supports more than one cutting tool or tooth.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIGS. 1a-1c are a perspective view 1 a, a front view 1 b, and a sideview 1 c of a stump cutting apparatus according to the presentinvention;

FIG. 2 is an exploded perspective view of a stump cutting apparatusaccording to the present invention;

FIG. 3 is an exploded perspective view of a tool holder and cuttingtooth of the stump cutting apparatus according to the present invention;

FIGS. 4a and 4b are a rear view of the tool holder and a fastener usedto secure the tool holder 4 a and a cross-sectional view taken alonglines B-B showing the fastener extending through the tool holder 4 b;

FIGS. 5a and 5b are a front view of the tool holder and cutting tool ortooth according to the present invention 5 a and a cross-sectional viewtaken along lines B-B of FIG. 5a showing the cutting tool or toothsecured in the tool holder 5 b;

FIGS. 6a-c are a partial front view of a stump cutting apparatusaccording to the present invention 6 a, an enlarged front view of thetool holder as attached to a wheel of the stump cutting apparatus takenin circle b-b of FIG. 6a , and an enlarged partial cross-sectional sideview of the stump cutting apparatus taken along lines d-d of FIG. 6 b;

FIGS. 7a-7c are a perspective view of a wheel of the stump cuttingapparatus according to the present invention 7 a, a front view of awheel of the stump cutting apparatus according to the present invention7 b, and a side view of a wheel of the stump cutting apparatus accordingto the present invention 7 c;

FIGS. 8a-8c are a perspective view of the tool holder of the stumpcutting apparatus according to the present invention 8 a, a side view ofthe tool holder of the stump cutting apparatus according to the presentinvention 8 b, and a front view of the tool holder of the stump cuttingapparatus according to the present invention 8 c;

FIGS. 9a-9c are a perspective view of a wheel block of the stump cuttingapparatus according to the present invention 9 a, a front view of thewheel block of the stump cutting apparatus according to the presentinvention 9 b, and a side view of the wheel block of the stump cuttingapparatus according to the present invention 9 c;

FIGS. 10a-10c are a rear perspective view of a spacer used in connectionwith the tool holder 10 a, a front perspective view of the spacer 10 b,and a side view of the spacer 10 c of the stump cutting apparatusaccording to the present invention;

FIGS. 11a-11c are a perspective view of a tool holder and cutting toolsor teeth secured thereto 11 a, a front view of the tool holder andcutting teeth 11 b and a side view of the tool holder and cutting toolsor teeth 11 c according to the present invention;

FIG. 12 is a front view of a tool holder illustrating one orientation ofthe arm members and correspondingly the cutting tools or teeth accordingto the present invention;

FIG. 13 is a partial schematic view showing the cut profile or path of astump cutting apparatus according to the present invention;

FIG. 14 is a partial schematic view illustrating the swing path or arcof a stump cutting apparatus; and

FIGS. 15a-15c are schematic illustrations of various positions of thecutting tip illustrating different patterns, locations or positions ofthe cutting tip according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

FIGS. 1a-1c illustrate a stump cutting apparatus, seen generally at 10,according to one embodiment of the present invention. The stump cuttingapparatus 10 generally includes a wheel 12, a tool holder 14, a holderblock 16, and a plurality of cutting tools or cutting teeth 18 securedto the tool holder 14. As illustrated, the cutting tools 18 are locatedabout the periphery or peripheral edge 20 of the wheel 12.

FIGS. 2 and 7 a-7 c illustrate one example of the present inventionwherein the wheel 12 is a plate-like member mounted for rotation aboutan axis 22 in the direction of the arrow 24. The wheel 12 rotates in agenerally circular pattern as defined by a radius or radial 41 rotatedabout the axis 22. While the term “wheel” is used herein, it broadlyrefers to any member rotated about a hub in a manner similar to a wheeland is not limited to a circular disk. For example, one or more radiallyextending tool support segments 26 connected to the hub 15 a wouldcomprise a “wheel.”

As illustrated in the disclosed example the wheel 12 includes sidesurfaces 12 a and 12 b and a generally arcuate outer surface 28 locatedat the periphery or peripheral edge 20 of the wheel 12. The wheel 12further includes a central aperture 15 surrounded by a plurality ofsmaller apertures 17 suitable for securing the wheel 12 to a stumpgrinding machine. The area or portion 15 a of the wheel 12 located aboutor around the central aperture 15 is generally termed the hub 15 a. Asillustrated in FIG. 7c the dotted lines 23 represent the circumferenceof the wheel 12 and show sections of the wheel 12 which have beenremoved thereby forming a plurality of outwardly extending members ortool support segments 26, as illustrated each of the tool supportsegments 26 extending outward in an arm-like fashion. While shown as aone piece member, the wheel 12 could be fabricated formed of two piecesincluding a hub 15 a and at least one outwardly extending member or toolsupport segment 26 attached to the hub 15 a.

As illustrated, the generally arcuate outer surface 28 forms the distalend of the tool support segment 26 and has a curvature associated withthe circumference of the wheel 12 as established by the radius or radial41 extending outwardly from the axis 22 and terminating at theperipheral edge 20. The curvature may change such that it is swept backand lies under the circumference of the wheel 12. Additionally, theconfiguration of the outer surface 28 of the tool support segment 26 maybe something other than arcuate.

Each tool support segment 26 includes a forward facing support surfaceor mounting surface 30 extending outwardly along a radial 34 extendingoutwardly from the axis 22. As disclosed further herein, the tool holder14 is connected to the wheel 12 at the support or mounting surface 30.The support or mounting surface 30 is a flat or planar surface extendingbetween the respective sides 12 a, 12 b of the wheel 12. Thus, the planeof the support or mounting surface 30 lies in or is parallel to the axis22 of rotation. Accordingly, the support or mounting surface 30 is aforward facing surface with respect to the direction 24 of wheel 12rotation. FIG. 1c illustrates the respective support surfaces 30 ofopposite tool support segments 26 extending along a line or planepassing through the axis 22. In the illustrated embodiment, the supportor mounting surfaces 30 of the respective tool support segments 26 arelocated on or forward of a line or plane passing or extending throughthe axis 22 between opposing peripheral edges of the wheel 12; such as aline representing a diameter of the wheel 12. In an additionalembodiment, the support surface 30 of the tool support segment 26 may beangled, canted or skewed with respect to the plane; however, in anadditional embodiment the distal end of the support or mounting surface30, that is the end at the intersection of the support or mountingsurface 30 and the outer surface 28 of the tool support segment 26,remains at or forward of the plane. As used herein the terms forward andrearward are based upon the direction of rotation of the wheel 12 duringthe cutting operation. For example, since the tool support segments 26rotate in the direction 24 about the axis 22, with the plane alsorotating in the direction 24, the area to the left of the plane isforward in the area to the right is rearward. Thus, the proximal end ofthe support or mounting surface 30 may be located forward or rearward ofthe plane.

While the support or mounting surface 30 is illustrated in the disclosedexample as planar, it may also be V-shaped, stepped, serrated,elliptical, concave or convex. Since the tool holder 14 is secured tothe support or mounting surface 30, the tool holder 14 should have acorresponding or complementary shape to that of the support or mountingsurface. In addition, the support or mounting surface 30 may have awidth greater than the width or thickness of the wheel 12, with thewidth or thickness of the wheel being the distance between therespective side surfaces 12 a, 12 b of the wheel 12 at a location spacedfrom the support surface 30, for instance at the hub 15 a. In oneexample, the support or mounting surface 30 may extend laterallyoutwardly whereby it has a width substantially equal to the width of thetool holder 14 with the width or thickness of the support surface 30tapering inwardly until it reaches the width or thickness of the wheel12. Increasing the width or lateral thickness of the support or mountingsurface 30 provides additional support to the tool holder 14.

As illustrated, portions or sections of the wheel are removed, with theremoved sections of the wheel 12 equating to that portion of the wheel12 located in front of the support surface 30. The removed sectionincludes an area subtended by a chord 38 intersecting with a radial 34or line 36 extending through the center or rotational axis 22 of thewheel 12. Accordingly, the tool support segments 26 extend between aradial 34 or line 36 and a chord 38 of the generally circular cuttingwheel 12; wherein the surface extending along the radial 34 or line 36is the forward or support surface 30 and the surface extending along thechord 38 is the rear or trailing surface 40. While the removed sectionscooperate with the tool support segments 26 to provide clearance andassist in mounting the tool holders 14, they also provide increasedvisibility during the cutting operation and reduce the overall weight ofthe stump cutting apparatus 10. If desired, the wheel 12 can begenerally circular with a plurality of radially inwardly extending slotsinto which the holder blocks 16 are secured.

The rear or trailing surface 40 of the cutting wheel 12 provides accessto the tool holder 14 located on the following or trailing tool supportsegment 26. It also provides clearance for the fasteners 56 used forsecuring the tool holder 14 to the support surface 30 of the toolsupport segment 26. As illustrated, the tool holder 14 is located in aslot or notch 42 formed by the support surface 30 and a shoulder 44having a beveled leading surface 46 and a rear surface 48. Asillustrated in FIGS. 1a-1c the tool holder 14 is placed in the slot ornotch 42 and situated between the support surface 30 and the rearsurface 48 of the shoulder 44. The rear surface 48 of the shoulder 44provides support to the lower end of the holder 14 during the cuttingoperation. While the shoulder 44 provides additional support, it may beeliminated or removed.

Each tool support segment 26 includes a cavity or opening 58 locatedrearwardly of the support surface 30 of the tool support segment 26. Aplurality of through bores or apertures 60 extend from the supportsurface 30 to the cavity or opening 58. The cavity or opening 58 issized to receive the holding block 16. As illustrated in FIG. 7c theapertures 60 extend rearwardly from and substantially perpendicular tothe support surface 30. In additional embodiments, the apertures 60extend rearwardly but are skewed, either outward towards the periphery20 of the wheel or inward toward the hub or rotational axis 22 of thewheel 12, with respect to the longitudinal axis/plane of the support ormounting surface 30. As illustrated, the apertures 60 extend rearwardlyfrom the support or mounting surface 30 between the respective sidesurfaces 12 a, 12 b of the wheel 12. Accordingly, the apertures 60 liein or are parallel to the plane of the wheel 12 rather than transverseor across the plane of the wheel 12.

As illustrated, in FIGS. 1a-1c and FIGS. 3-6 c and 8 a-8 c according tothe one example of the present invention, the tool holder 14 is a onepiece member having a central longitudinal axis 32 and a mounting orbase portion 49 and a tool support portion 51. The tool support portion51 includes a plurality of outwardly extending arms or support members92. The tool holder 14 further includes a front or leading surface 52and a rear or trailing surface 54 interconnected by respective sidesurfaces 53, 55. As illustrated, when viewed from the front or leadingsurface 52 the tool support portion 51 is wider or larger than the baseportion 49. In different embodiments, the width or size of the baseportion 49 and tool support portion 51 are variable wherein each may bethe same or similar size or the base portion 49 may be larger than thetooth support portion 51. Further, the tooth support portion 51 may beseparable from the base portion 49 with the tool holder 14 fashioned asa two-piece or multi-piece member.

A plurality of apertures 50 a, 50 b extend through the tool holder fromthe front or leading surface 52 to the rear or trailing surface 54. Theapertures 50 a, 50 b receive fasteners 56 used to secure the tool holder14 to the cutting wheel 12. The fasteners 56 extend through theapertures 50 a, 50 b, the corresponding apertures 60 located in the toolsupport segment 26 and into threaded bores 62 located in the holdingblock 16. The threaded portions 74 of the fasteners 56 cooperate withthe threaded bores 62 of the holder block 16 whereby rotation of thefasteners 56 draws the holder block 16 into engagement with the cuttingwheel 12; specifically, the leading surface 58 a of the cavity oropening 58. Continued rotation of the fasteners 56 draws rear ortrailing surface 54 of the tool holder 14 into engagement with thesupport surface 30 of the tool support segment 26 of the cutting wheel12. The holder block 16 cooperates with the fasteners 56 to secure thetool holder 14 on tool support segment 26 of the cutting wheel 12. Theholder block 16 is sized such that it fits within the cavity or opening58 thereby reducing abrasion or wear of the type typically seen whenusing a nut in a stump cutter apparatus. Since the holder block 16 iswithin the cavity or opening 58 it is not subjected to abrasive/wearforces occurring during the stump cutting/grinding operation.Additionally, use of the holder block 16 reduces the amount of partsnecessary; specifically, only one holder block 16 is needed rather thantwo nuts.

As set forth previously, the width of the front or leading surface 52 ofthe tool holder portion 51 is wider than width of the front or leadingsurface the base portion 49. While shown with the respective sides 53,55 tapering outwardly starting at a point located below the upperaperture 50 a and continuing up to the support member 92 other shapescan also be used provided they support the respective cutting tools 114in the spaced relationship to be described later. As illustrated in FIG.6c the tool holder 14 is located on the wheel 12 wherein the lower endof the base portion 49 is positioned in the slot or notch 42 such that aportion of the front surface 52 of the tool holder engages the rearsurface 48 of the slot or notch 42 and the rear surface 54 of the toolholder 14 engages the support surface 30. At least a part of the toolholder portion 51 extends above the contact point 208, with contactpoint 208 being that point where the rear surface 54 of the tool holder14 contacts the generally arcuate outer surface 28 of the peripheraledge 20 of the wheel 14. Accordingly, as the wheel 14 rotates in thedirection of the arrow 24 contact with a stump generates a force (F) onthe cutting tool 114 and correspondingly the tool holder 14. The force(F) creates a moment about the contact point 208 that would cause thetool holder 14 to pivot about the contact point 208; however, the pivotforce or moment is resisted both by locating the end or bottom of thetool holder in the slot or notch 42 and the fasteners 56. The force (F)generated during the stump cutting or grinding operation is transferredthrough the cutting tool 114 to the tool holder 14 and directly to thewheel 12 and correspondingly reducing the shear load placed on thefasteners 56. Thus the impact force of the cut or grinding operation isborne by the wheel 12 not the fasteners 56. Accordingly, the fasteners56 act to secure the tool holder 14 to the wheel 12 with the shear loadapplied at the contact point 208. Reducing the shear load on thefasteners 56 reduces the potential for fastener or bolt 56 failure.

The fasteners 56 are oriented such that they extend in or are parallelto the plane of the cutting wheel 12. As shown, the fastener 56 istransverse to or crosses a radial 34 while remaining parallel to theplane of the cutting wheel 12. As illustrated in FIGS. 3-6 the apertures50 a, 50 b of the tool holder 14 extend longitudinally in the samegeneral direction as the apertures 102 a-c located in the tool holder14. That is, they are oriented in the direction of rotation 24 of thewheel 12.

While the holder block 16 is the preferred embodiment for securing thetool holder 14 to the wheel 12, the holder block 16 could be removed andthe through bores or apertures 60 could be threaded. For example, thewheel 12 could have threaded apertures that threadably receive thefasteners 56 thereby eliminating the cavity or opening 58 in the wheel12 and the holder block 16. In this instance, the fasteners 56 wouldextend into the wheel 12 in or parallel to the plane of the wheel 12.Using the holder block 16 in cooperation with the through bores orapertures 60 extending into the cavity or opening 58 provides afastening arrangement that makes it easier to replace should the bolt orfastener 56 break; that is it is easier to remove the broken fastenerand holder block 16 assembly rather than have to remove the brokenfastener from a threaded aperture in the wheel 12. In addition, such anarrangement eliminates wear in the wheel should threaded apertures beused therein specifically, installation and removal of the tool holder14 may cause the wallowing and potential stripping of the threadedapertures in wheel 12.

Turning now to FIGS. 3-5 b, as set forth previously, the rear ortrailing surface 54 is the surface that contacts or is placed adjacentto the support surface 30 of the tool support segment 26. As illustratedin FIG. 4b the apertures 50 a, 50 b may each include a countersunkportion 64 that includes a conical or beveled surface 66 that receivesand mates with the conical or beveled shoulder 70 located on the head 72of the fastener 56. As illustrated the fastener 56 has a threadedportion 74 and a drive socket 76 located on the head 72 of the fastener56. The drive socket 76 is shown herein as a hexagonally shaped socketused to receive a hex head drive member. The threaded portion 74 of thefastener 56 also includes an engagement portion, shown herein as a slot78 (see FIGS. 4a and 6c ) used to remove the threaded portion should thefastener 56 fracture wherein the threaded portion 74 is separated fromthe head portion 72 and correspondingly the drive socket 76.

As illustrated in FIGS. 4b and 6c since the tool holder 14 isreversible; it is a mirror image about a plane 88 extendinglongitudinally between the front surface 52 and rear surface 54 of thetool holder 14 and perpendicular to the apertures 50. Accordingly, thetool holder 14 can be rotated 180° about a central longitudinal axis 32,see FIG. 3, whereby the front or leading surface 52 becomes the rear ortrailing surface 54. The apertures 50 have opposed countersunk portions64 each having a conical or beveled surfaces 66 located on both thefront or leading surface 52 and a rear or trailing surface 54. In short,there are countersunk portions 64 on both surfaces 52, 54 suitable forreceiving the head 72 of the fastener 56. Thus, should any damage resultto the front or leading surface 64 of the tool holder 14 it may beflipped over and reattached to the cutting wheel 14 whereby the rear ortrailing surface 54 becomes the front or leading surface 52.

Because there are countersunk portions on both surfaces 52, 54 a spacer80 having an aperture 82, a conical or beveled surface 84 and a flatsurface 86 is placed in the countersunk portion 64 located in the rearor trailing surface 54 of the tool holder 14 located opposite the head72 of the fastener 56. The spacer 80 is sized to fit into and fill thecountersunk portion 64 located in the rear or trailing surface 54whereby the rear or flat surface 86 is flush with the rear or trailingsurface 54 such that it engages the support surface 30 on the toolsupport segment 26.

As disclosed, the tool holder 14 also includes a cutting tool or cuttingtooth 114 located on the arm or support member 92 extending outwardlyfrom the tool support portion 51. As illustrated the tool holder 14includes a plurality of individual arm members 92, including a centerarm member 92 a, a left arm member 92 b and a right arm member 92 c witheach of the arms being separate from one another with a space or gap 93located between adjacent arm members 92 a-92 c. The gap 93 providing apath for chip flow and reducing the profile of the tool holder 14 andcorrespondingly chip deflection. Further, as set forth below, dependingupon the location of the cutting tool or tooth 114, the space or gap 93reduces the opportunity for the tool holder 14 to strike the stumpduring the cutting or grinding operation.

A cutting tool or tooth support portion 96 is located at the end of thearm or support member 92 and extends longitudinally in a directionbetween the respective front or leading surface 52 and rear or trailingsurface 54. The tooth support portion 96 includes first and second ends98, 100 with an aperture 102 extending longitudinally through the toothsupport portion 96 between the first and second ends 98, 100. Asillustrated herein, the tooth support portion 96 includes an innersurface as defined by the aperture 102 and an outer surface. The outersurface of the tooth support portion 96 may be greater than the width orthickness of the arm or support member 92, with the thickness defined asthe distance between the respective side surfaces 104, 106 of eachsurface of the arm or support member 92. A pair of flat surfaces orshoulders 108 are located on the arm or support member 92 adjacent thefirst and second ends 98, 100 of the boss 96. The first and second ends98, 100 have a generally planar or flat surface 110 with a chamferedportion 112 extending between the flat surface 110 and the aperture 102.As illustrated, the chamfered portions 112 are located at both ends ofthe aperture 102.

As illustrated, the tooth support portion 96 of the tool holder 14supports a cutting tool often referred to as a cutting tooth 114 havinga head 116. The head 116 having a front surface 118 and a rear surface120. A cutting tip 122 is attached to the front surface 118 of the head116. The cutting tip 122 is generally cylindrical in shape and the frontsurface thereof has a generally concave shape which terminates prior toor at the periphery of the cutting tip 122. The front surface 118 of thehead 116 may include a shallow depression or indentation 124 sized toreceive a corresponding projection 126 extending outward from the rearsurface 128 of the cutting tip 122. The complementary indentation 124and projection 126 are such that the projection 126 functions toproperly locate and orient the cutting tip 122, typically made of a hardmaterial such as carbide, on the head 116 prior to attaching the cuttingtip 122 to the head 116 through one of several known processes includingbrazing.

As illustrated, the head 116 has a generally cylindrical shape thattapers rearwardly from the front surface 118 toward the rear surface120. A plurality of planar indentations 130 are located about the outercircumferential surface of the head 116. As illustrated in the disclosedembodiment, the planar indentations 130 are spaced from one another apredetermined amount, illustrated herein as 120°. When the planarindentations 130 located on the head 116 matingly engage the planar orflat surface or shoulder 108 located on the arm member 92 they cooperatewith the shoulder 108 to resist rotation of a cutting tool or tooth 114about its longitudinal axis 132. The multiple planar indentations 124located on the head 116 of the cutting tool or tooth 114 make thecutting tooth 114 indexable.

The cutting tool or tooth 114 further includes a shank 134. The shank134 has a proximal end 136 and a distal end 138 with the proximal end136 attached to the rear surface 120 of the head 116. A fillet 140extends between the rear surface 120 of the head 116 and the outerperiphery of the shank 142. The fillet 140 is a chamfered surfaceextending between the respective rear surface 120 of the head 116 andthe shank 134 and operates to reduce the stress concentration at thejoint between the head 116 and the shank 134. As illustrated, the shank134 is a generally cylindrical member. The distal end 138 of the shank134 includes a threaded portion 144.

Accordingly, the cutting tool or tooth 114 is installed or positioned inthe aperture 102 located in the arm member 92 by inserting the distalend 138 of the shank 134 in the aperture 102 and pushing the shank 134through the aperture 102 until the head 116 of the cutting tool or tooth114 is placed adjacent the first or front end 98 of the boss 96 and thethreaded portion 144 extends outwardly past the rear or second end 100.A nut 146 threadably engages the threaded portion 144 to secure thecutting tool or tooth 114 to the arm member 92. Since both the first orfront end 98 of the boss 96 and the second or rear end 100 of the boss96 both have chamfered portions 112 adjacent the flat surfaces 110 aspacer 148 having an aperture 150 is placed between the boss 96 and thenut 146. The spacer 148 includes a chamfered or beveled portion 152 thatengages the chamfered portion 112 of the boss 96 when the nut 146 istightened to secure the cutting tool or tooth 114 to the arm member 92of the tool holder 14. The spacer 148 also functions to provideadditional clearance for the nut 146 as it moves the nut 146 rearwardlyalong the longitudinal axis 132 of the cutting tool or tooth 114 suchthat it clears the respective shoulder 108 of the boss 96. Accordingly,the nut 146 acts on the spacer 148 whereby the diameter or overall sizeof the nut 146 is not limited by the shoulder 108 of the boss 96.

As illustrated in FIG. 12, the tool holder 14 has a center arm member 92a, a left arm member 92 b and a right arm member 92 c. Each of the armmembers 92 a, 92 b, 92 c having a similar construction includingrespective apertures 102 a, 102 b, 102 c. Each of the respectiveapertures 102 a, 102 b, 102 c having a center point 154 a, 154 b, 154 c.The tool holder 14 further includes mounting apertures 50 a, 50 b bothhaving respective center points 156 a, 156 b. As set forth earlier thetool holder 14 is reversible; accordingly, the tool holder 14 is amirror image about a plane 158 passing through the respective centerpoints 154 a, 156 a, 156 b of the arm member 92 a and mounting apertures50 a, 50 b and containing the longitudinal axes of the respectiveapertures 102 a and mounting apertures 50 a, 50 b.

As illustrated, the apertures 102 b, 102 c of each of the left armmember 92 b and the right arm member 92 c are spaced outwardly, andradially inwardly—toward the axis 22, from the aperture 102 a located inthe center arm member 92 a. As illustrated the center points 154 b, 154c of the apertures 102 b, 102 c are located or offset at an angle of 69°with respect to the plane 158. This angle and spacing of the centerpoints 154 b, 154 c of the respective apertures 102 b, 102 c of the leftarm member 92 b and the right arm member 92 c may vary depending uponthe size and position of the cutting tip 122 of the cutting tooth 114placed in the respective arm members 92 a, 92 b, 92 c. For example, inone embodiment, when using a circular cutting tip 122 of the typedisclosed herein, adjacent the cutting tips 122 are positioned such thatthe top of the cutting tip 122 located in aperture 102 b is located at apoint radially inwardly approximately one half of the diameter of anadjacent cutting tip 122 located in aperture 102 a. See for example FIG.13, wherein the cutting tip 122 of the cutting tooth 114 located in armmember 92 c engages the workpiece or stump at point 180 and leaves cutpath 162. As further illustrated, cutting tip 122 of the cutting tooth114 located in arm member 92 a engages the workpiece or stump at point182 which is located at approximately half of the diameter of thecutting tip 122 and leaves a cut path 166. While the cut path 162illustrated in FIG. 13 is not shown to encompass the entire semicircularportion of the cutting tip 122 of the cutting tooth 114 located in armmember 92 c this is for illustration purposes only, it is contemplatedto use one half of the cutting tip 122 of each cutting tooth 114 locatedin the respective arm members 92 b, 92 c.

As known, during a stump cutting or grinding operation the stump cuttingapparatus typically moves or swings the cutting wheel back and forth ina side to side motion. Initially, the apparatus swings or moves thecutting wheel either to the right or to the left to cut or grind away aportion of the stump. Upon completing the first swing or pass, thecutting wheel moves forward towards the stump, after which the wheelswings in the opposite direction. FIG. 13 illustrates one example of thecut path or profile of the stump cutting apparatus 10 according to thepresent invention. As the apparatus 10 moves to the left, in thedirection shown by arrow 160, the cutting tooth 114 located in the armmember 92 c generates, as shown in the schematically illustrated stump,a cut profile 162 while the cutting tooth 114 located in the arm member92 a generates a cut profile 166. Once the cut path is completed in adirection 160, the cutting wheel 12 moves forward in the direction ofthe arrow 168 and the cutting wheel 12 then moves or swings to theright, that is in the direction of the arrow 170, whereby the cuttingtooth 114 located in arm member 92 b engages the stump 164 first and thecut path or profile is the same only in the opposite direction; that isthe cutting tooth 114 located in the arm member 92 b will cut firstafter which the cutting tooth 114 located in the arm member 92 a, thecenter arm member, will also grind or cut the stump. It should beunderstood that as the wheel swings to the left and right or back andforth in the direction of the arrows 160, 170 the center cutting tooth114 located in arm member 92 a will cut in both directions while therespective side cutting teeth 114 cut in one direction only.

FIGS. 15a-c schematically illustrate different positions or locations ofthe respective cutting tips 122 a-122 c. As discussed, the arm members92 a-92 c are oriented such that they position the cutting tips 122a-122 c. FIGS. 15a-15c illustrate several preferred embodiments of theposition of the respective cutting tips 122 a-122 c. For example, asillustrated in FIG. 15a of the cutting tips 122 a-122 c are spacedlaterally to a distance (d) and are spaced vertically a distance (v).Accordingly, when moving through the cutting path or moving back andforth in the direction of the arrow 160 cutting tip 122 c may engage theworkpiece or stump at up to 180° of its periphery; that is, the area ofthe periphery located in quadrants 1 and 2. With respect to cutting tip122 a, only that periphery of the tip above the line (L) would engagethe workpiece. Accordingly, as the angle (θ) increases the area oramount of the periphery of the cutting tip 122 and that engages theworkpiece or stump increases, see FIGS. 15b and 15c . FIG. 15cillustrates the angle (θ) at 45°. When the angle (θ) reaches 45° 180° ofthe periphery of the cutting tip 122 a, the periphery of the quadrants 1and 2, will engage the workpiece as the top 122 e of the cutting tip 122c is at the same vertical height or level as the bottom 122 f of thecutting tip 122 a. For example, if each cutting tip 122 a and 122 c hada diameter of 1 inch then the position of the cutting tips 122 a and 122c would enable an operator to cut or grind a two (2) inch portion of theworkpiece or stump in a single pass in the direction 170. Because thecutting tip 122 b is mounted in a mirror image position of the of 122 cthe operator could then cut or grind a 2 inch portion of the workpieceor stump as the apparatus moves in a direction 160. Because the operatormay not wish to fully engage the periphery of the cutting tip 122 c;that is, cut with less than 180° of the periphery of cutting tip 122 c,and use for example only 120° of the periphery of the cutting tip 122 c,then the angle can be changed so a corresponding portion of theperiphery of the cutting tip 122 a would also only utilize 120° of theperiphery of the cutting tip 122 a.

FIG. 15b illustrates a cutting tip pattern or location wherein when theapparatus moves in the direction 170, 180° of the periphery of cuttingtip 122 c engages the workpiece and only 90° or quadrant 1, of theperiphery of the cutting tip 122 a engages the workpiece. However, whenthe apparatus travels in the other direction as illustrated by arrow 160then 180° of the periphery of the cutting tip 122 b engages theworkpiece while only 90°, quadrant 2, of the periphery of the cuttingtip 122 a engages the workpiece. Accordingly, during operation only onehalf of the periphery of each cutting tip 122 a-122 c is used.Accordingly when the tooth becomes worn the tooth may be removed as setforth above and rotated to expose a new, fresh and sharp cutting tip.

As disclosed, the respective cutting tips 122 a-122 c of each of FIGS.15a-15c are spaced a distance (d) which provides clearance between therespective cutting tips and allows for chip passage, flow and discharge.If for example, referring to FIG. 15c , changing only the angle (θ) toan amount greater than 45° results in a vertical space or gap betweenthe top 122 e the cutting tip 122 c and the bottom 122 f of the cuttingtip 122 a resulting in material that would not be removed. Further, itwould decrease the distance (d) between the cutting tip 122 a and 122 cthus reducing the clearance space for chip passage, flow and discharge.The teeth 114 are placed in a substantially triangular formation withthe center tooth 144 a positioned in the plane of the wheel 12 with theoutwardly positioned teeth 114 b and 114 c spaced from the respectivesides of the wheel 12. That is, the center tooth 114 a is located abovethe peripheral edge 20 and centered between the respective sides 12 aand 12 b of the wheel 12 with the outwardly positioned teeth 114 b, 114c spaced accordingly.

As stated, FIGS. 15a-15c illustrate several examples of the tooth 114placement. With one aspect of the present invention being that the armmembers 92 allow infinitely variable tooth 114 placement whereby thecutting tips 122 can be placed in many different cutting positions. Withthe positions also variable depending upon the shape or configuration ofthe cutting tip 122; for example while shown as circular it could alsobe square, triangular or take other shapes.

Further, the can be arranged such that the arm members support the tooth114 placement such that all of the cutting surfaces of the cutting tips122 a-122 c are located above the peripheral edge 20 of the wheel 12.

Accordingly, the spacing and orientation of the respective cutting teeth114 as determined by the position of the respective arm members 92 a, 92b, 92 c can be modified depending upon cutting tip configuration, thedesired cut path or profile and the arc or path of the swing or back andforth movement of the cutting wheel.

While illustrated in FIG. 13 as moving in a lateral or back and forthdirection, many stump cutting machines use cutting wheels that swing orpivot about a pivot point 190 whereby the cutting tools 114 travel in anarc 192, see FIG. 14. Accordingly, the position or orientation of therespective cutting teeth may vary depending upon the particular swingarc of the cutting tool; specifically, the cutting tools 114 located inrespective left arm member 92 b and right arm member 92 c be positionedinward, closer to the plane 158 in order to ensure that the backsidecutting tool 114; i.e. the cutting tool 114 located on the side oppositethe direction of cutting wheel 12 swing or movement does not engage orrub on the stump. In the alternative, respective left arm member 92 band right arm member 92 c may be positioned radially inward; however,radially inward movement is limited by the respective cut path orprofile of the cutting tool 114 located in the center arm member 92 a.

In addition, according to the present embodiment the cutting tips 122 ofthe respective cutting teeth 114 located in the center arm member 92 a,left arm member 92 b and right arm member 92 c are all located in thesame plane 182, see FIG. 1c and FIG. 11c . The plane 182 may extendacross the plane of the cutting wheel 12. In one embodiment, the plane182 is parallel to the plane of the support surface 30 andcorrespondingly to the front and rear surfaces 32, 54 of the tool holder14. It may also be parallel to the axis of rotation 22. Wherein theshanks 134 of the respective cutting tools or teeth 114 extendingtransverse to a radial 41 extending outwardly from the axis 22. Inanother embodiment, the plane 182 contains the axis 22. That is, sincethe flat surfaces 110 of the respective first ends 96 of the bosses 96of each of the center arm member 92 a, left arm member 92 b and rightarm member 92 c are all located in a common plane, see FIGS. 8a-8c ,then the respective cutting tips 122 are also located in or contact acommon plane, see FIG. 11 c.

It may also be advantageous to stagger the spacing of the respectiveleft arm member 92 b and right arm member 92 c and correspondingly thatof the cutting teeth 114 associated therewith whereby they may be placedeither behind or forward of the cutting tooth 114 located in the centerarm member 92 a. That is the plane 182 of the cutting teeth 114 locatedin the left arm member and right arm member 92 b, 92 c can be locatedahead of or behind the plane of the cutting tooth 114 located in thecenter arm member 92 a. As used herein ahead of means first in thedirection of rotation 24; that is, a cutting tooth located ahead ofanother cutting tooth would engage the workpiece or stump first.

As illustrated, the stump cutting apparatus 10 includes a cutting wheel12 and tool holder 14 combination as set forth above shows that thecutting tools or teeth 114 are located in the respective left arm member92 b and right arm member 92 c at the same distance from the centerpoint 22 a of the axis 22 of the cutting wheel 12. Specifically asillustrated in FIG. 1a-1c and FIG. 2 the cutting wheel 12 has arotational axis 22 and a center point 22 a. In addition, four toolholders 14 are illustrated spaced about and mounted to the cutting wheel12. Each of the tool holders 14 holding three cutting tools or teeth114. Accordingly, all of the cutting tools or teeth 114 located in eachof the respective right arm members 92 c are located the same distanceor are equidistant from the center point 22 a. That is, the distancefrom the center point 154 c of the right arm member 92 c to the centerpoint 22 a is the same for each of the tool holder 14 mounted to thecutting wheel 12. Accordingly, all are at a common distance from theaxis 22 and rotate in a common plane. As illustrated in FIG. 1b all ofthe cutting tools or teeth 114 are located in or rotate in a commonplane 172. That is, all of the cutting tools or teeth 114 located in theleft arm member 92 a are all spaced the same horizontal or lateraldistance from the side 12 a of the wheel 12. Thus, as the wheel 12rotates, all of the cutting tools or teeth 114 secured in the respectiveleft arm member 92 a rotate in the same circular path 180. Further, itis contemplated that the tool holder 14 may include additional armmembers 92; for example, an additional arm member 92 can be added withthe additional arm member extending outwardly further than the currentarm member 92 a. Accordingly, the lateral spacing from the wheel of theadditional arm member would be greater than the lateral spacing ofcurrent arm member 92 a. Should such additional arm members be added,the corresponding cutting tools or teeth located therein will all rotatein the same circular path.

Therefore it can be put in two ways, all of the cutting tools or teethrotating the same circular path have the same lateral spacing from theside of the wheel or all of the teeth at a particular lateral spacingrotate in the same circular path centered about the axis 22 of the 12.Accordingly, additional tool holders can be added to the wheel 12, withthe additional tool holders having cutting tools or teeth havingdifferent lateral spacing with respect to the side 12 a of the wheel 12or distance from the axis 22; however, for each cutting tool or tooththe spacing and distance must remain the same so that all of the teethrotating in the same circular path must be spaced the same distance fromthe wheel. Further, it is contemplated that as the lateral spacing fromthe side 12 a of the wheel 12 increases that the distance from the axis22 decreases.

As set forth above, the same holds true for any other grouping ofcutting tools or teeth 114 mounted in any of the other arm members 92 aor 92 b. Further, while shown with only three arm members 92 a, 92 b, 92c this is for the purposes of illustration only, adding additional armmembers to the respective tool holder 14 is within the bounds of thecurrent invention. Further, additional tool holders having different armmember configurations; i.e. tool holders having arm members supportingcutting tools or teeth positioned in the gaps or spaces between the armmembers of the current tool holders. Specifically, while the cuttingwheel 12 shows four tool holders 14 spaced approximately 90° from oneanother, it is contemplated that the cutting wheel 12 could be modifiedto include additional tool holders secured to the wheel 12 between therespective tool holders. These additional tool holders can have adifferent arm member configuration from the tool holders 14 and thussecure cutting tools or teeth that rotate in a different circular path.

Further, while the cutting tips 122 of the cutting tools or teeth 114are shown having a generally circular concave or cup shaped surface,other cutting tip configurations such as square, triangular or ovalincluding combinations or portions thereof are contemplated.Accordingly, depending upon the configuration or shape of the cuttingtip, the arm members are positioned to enable cutting along a specificand predetermined cut path for each cutting tool or tooth 114.

The description of the invention is merely exemplary in nature and,thus, variations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

What is claimed is:
 1. A stump cutting apparatus comprising: a hubhaving an axis of rotation; a member extending outwardly from said huband having a plane of rotation transverse said axis of rotation, saidmember including a first side surface, a second side surface, said firstside surface and said second side surface generally parallel to theplane of rotation of said member, and a support surface extendingbetween said first side surface and said second side surface, saidsupport surface having a proximal end and a distal end with saidproximal end being closer to said hub; and a tool holder secured to saidsupport surface, said tool holder having a first arm, a second arm, anda third arm wherein said first arm supports a cutting tool locatedlaterally outwardly of said first side surface, said second arm supportsa cutting tool located laterally outwardly of said second side surfaceand said third arm supports a cutting tool located above a peripheralend of said member and generally between said first side surface andsaid second side surface.
 2. A stump cutting apparatus as set forth inclaim 1 including: said support surface having an aperture; and afastener received in said aperture in said support surface securing saidtool holder to said member.
 3. A stump cutting apparatus as set forth inthe claims 2 including: said member having an opening extending betweensaid first side surface and said second side surface; a holder blockpositioned in said opening in said member wherein said fastener engagessaid holder block to secure said tool holder to said support surface. 4.A stump cutting apparatus as set forth in claim 1 including a cuttingtool secured to said tool holder.
 5. A stump cutting apparatus as setforth in claim 1 including said tool holder supporting a plurality ofcutting tools, each of said cutting tools having a cutting face, eachcutting face lying in a plane generally parallel to the axis ofrotation.
 6. A stump cutting apparatus as set forth in claim 1 includingsaid tool holder supporting a plurality of cutting tools, said cuttingtools spaced at a different radial distance from the axis of rotation.7. A stump cutting apparatus as set forth in claim 1 wherein saidsupport surface is parallel to the axis of rotation.
 8. A stump cuttingapparatus as set forth in claim 1 including a plurality of membersextending from said hub and a support surface on each of said members,said support surfaces diametrically opposed such that said supportsurfaces lie in a common plane.
 9. A stump cutting apparatus as setforth in claim 1 including said member having a notch adjacent saidsupport surface and said tool holder positioned in said notch.
 10. Astump cutting apparatus as set forth in claim 1 including said toolholder having an aperture extending through said tool holder from saidfront surface to said rear surface wherein said tool holder is a mirrorimage about a plane extending longitudinally between said front surfaceand said rear surface of said tool holder and perpendicular to saidaperture in said tool holder.
 11. A stump cutting apparatus as set forthin claim 1 including said tool holder having an aperture extendingthrough said tool holder from said front surface to said rear surface,said aperture having a longitudinal axis; and said tool holder having aplurality of arms, each of said arms having an aperture therein each ofsaid apertures in said arms having a longitudinal axis wherein thelongitudinal axis of said aperture extending through said tool holderand the longitudinal axis of said aperture in said arms are parallel.12. A stump cutting apparatus as set forth in claim 1 including saidsupport surface having an aperture, said aperture in said supportsurface extending into said member between said first side surface andsaid second side surface; a fastener received in said aperture in saidsupport surface securing said tool holder to said member; and said toolholder supporting a plurality of cutting tools wherein a first cuttingtool is located laterally outwardly of said first side surface and asecond cutting tool is located laterally outwardly of said second sidesurface.
 13. A stump cutting apparatus as set forth in claim 1 includingsaid support surface having a first aperture and a second aperture, saidfirst aperture located at a different distance from said axis ofrotation than said second aperture.
 14. A stump cutting apparatus as setforth in claim 1 including a plurality of members extending from saidhub and a support surface on each of said members, a tool holder securedto each of said support surfaces, each of said tool holders supporting aplurality of cutting tools including a first cutting tool locatedlaterally outwardly of said first side surface and a second cutting toollocated laterally outwardly of said second side surface wherein thefirst cutting tools located laterally outwardly of said first sidesurface all lie in a first common plane transverse said axis of rotationand the second cutting tools located laterally outwardly of said secondside surface all lie in a second common plane transverse said axis ofrotation.
 15. A stump cutting apparatus comprising: a hub having an axisof rotation; a member extending outwardly from said hub and having aplane of rotation transverse said axis of rotation, said memberincluding a first side surface, a second side surface, said first sidesurface and said second side surface generally parallel to the plane ofrotation of said member, and a support surface extending between saidfirst side surface and said second side surface, said support surfacehaving a proximal end and a distal end with said proximal end beingcloser to said hub, said support surface having an aperture, saidaperture in said support surface extending into said member between saidfirst side surface and said second side surface.; and a tool holder,said tool holder having a base portion including a first side surface, asecond side surface, a front surface and a rear surface, an apertureextending through said base portion from said front surface to said rearsurface, said tool holder positioned such that said rear surface of saidtool holder is located adjacent said mounting surface of said member,said tool holder having a first arm, a second arm, and a third armwherein said first arm supports a cutting tool located laterallyoutwardly of said first side surface, said second arm supports a cuttingtool located laterally outwardly of said second side surface and saidthird arm supports a cutting tool located above a peripheral end of saidmember and generally between said first side surface and said secondside surface; a fastener, said fastener extending through said aperturein said base portion of said tool holder and into said aperture locatedin said support surface; and said tool holder supporting a plurality ofcutting tools wherein a first cutting tool is located laterallyoutwardly of said first side surface and a second cutting tool islocated laterally outwardly of said second side surface.
 16. A stumpcutting apparatus as set forth in claim 15 including a plurality ofmembers extending from said hub and a support surface on each of saidmembers, said support surfaces diametrically opposed such that saidsupport surfaces lie in a common plane.
 17. A stump cutting apparatus asset forth in claim 15 including a plurality of members extending fromsaid hub and a support surface on each of said members, a tool holdersecured to each of said support surfaces, each of said tool holderssupporting a plurality of cutting tools including a first cutting toollocated laterally outwardly of said first side surface and a secondcutting tool located laterally outwardly of said second side surfacewherein the first cutting tools located laterally outwardly of saidfirst side surface all lie in a first common plane transverse said axisof rotation and the second cutting tools located laterally outwardly ofsaid second side surface all lie in a second common plane transversesaid axis of rotation and wherein the first cutting tools lying in afirst common plane are located at a common radial distance from the axisof rotation and the second cutting tools lying in a second common planeare located at a common radial distance from the axis of rotation.
 18. Astump cutting apparatus comprising: a hub having an axis of rotation; asupport segment extending radially from said hub, said support segmentincluding a first side surface, a second side surface, a mountingsurface and a rear surface, said mounting surface extending between saidfirst side surface and said second side surface said mounting surfacehaving a proximal end and distal end, with said proximal end beingcloser to said axis of rotation; and said distal end located at aperipheral end of said support segment; said support segment having anopening extending from said first side surface to said second sidesurface and located between said mounting surface and said rear surface,said support segment further having an aperture extending from saidmounting surface to said opening; a tool holder, said tool holder havinga base portion including a first side surface, a second side surface, afront surface and a rear surface, an aperture extending through saidbase portion from said front surface to said rear surface, said toolholder positioned such that said rear surface of said tool holder islocated adjacent said mounting surface of said support segment, saidtool holder having a first arm, a second arm, and a third arm whereinsaid first arm supports a cutting tool located laterally outwardly ofsaid first side surface, said second arm supports a cutting tool locatedlaterally outwardly of said second side surface and said third armsupports a cutting tool located above a peripheral end of said supportsegment and generally between said first side surface and said secondside surface; a fastener, said fastener extending through said aperturein said base portion of said tool holder and said aperture of saidsupport segment; and a holder block positioned in said opening in saidsupport segment wherein said fastener engages said holder block tosecure said tool holder to said support segment.
 19. A stump cuttingapparatus as set forth in claim 18 including said tool holder supportinga first cutting tool is located laterally outwardly of said first sidesurface and a second cutting tool is located laterally outwardly of saidsecond side surface; and said first cutting tool having a cutting faceand said second cutting tool having a cutting face wherein said cuttingface of said first cutting tool and said cutting face of said secondcutting tool lie in a common plane, said common plane generally parallelto a plane containing the axis of rotation.